The present invention evolved from efforts to provide highly controlled uniform processing conditions in a food processor such as a smokehouse, cooker, dryer or the like. Food products typically processed include dried or dehydrated beef and beef sticks, fish, turkey, reconstituted bacon, beef chunks in stew, etc.
In a food processing chamber, moisture in the food product evaporates during a drying or heating process. The resulting water vapor increases the volume as well as the density of air leaving the processing chamber. It the amount of air entering and exiting the chamber is the same, water vapor from the food product is not efficiently withdrawn from the processing chamber. Water vapor in the chamber gradually increases, and consequently the humidity in the processing chamber increases, thus retarding the drying process.
The present invention addresses and solves the above noted and other problems regarding uniform and effective air flow and processing conditions. Uniform horizontal side air flow is provided across the surfaces of food products lying horizontally flat on pans or the like. A differential resistance to input and output air flow is established, and provides higher volume output air flow than input air flow and accommodates the extra volume of waver vapor due to moisture evaporating from the food. Perforated openings are sectionalized into a plurality of louver or damper sections. At the air supply or input side, the louvers are closed, forcing the air to enter the chamber through the perforations, or orifices in louvers achieving desirable velocity and direction of flow. At the air return side, the louvers are pivoted open, increasing the opening for air flow and reducing resistance. Bidirectional intermittent reversed flow is provided by reversing the roles of left and right sets of louvers.